ricotta, or even fresh paneer cheese would go well..Courgettes pair well with Fennel & Nigella seeds, so adding some of those spices in really hot oil before sauteeing the courgettes along with some scallions, may be an option..

Another option, meatless but delicious, would be to go in the direction of ratatouille, pairing your courgettes uup with small cubes of eggplant, pepper and onion. I'd also add thyme and oregano, as pierino suggested.

For something more sublime, you can add pieces of shrimp to the ratatouille filling, though chorizo is also a good one.